WASHINGTON — A military advisory commission is recommending that the Pentagon do away with a policy that bans women from serving in combat units, breathing new life into a long-simmering debate.

Though thousands of women have been involved in the fights in Iraq and Afghanistan, they have done so while serving in combat support roles — as medics, logistics officers and so on — because defense policy prohibits women from being assigned to any unit smaller than a brigade whose primary mission is direct combat on the ground. On Friday, a special panel was meeting to polish the final draft of a report that recommends the policy be eliminated “to create a level playing field for all qualified service members.”

If it were approved by the Defense Department, it would be yet another sizeable social change in a force that in the last year has seen policy changes to allow gays and lesbians to serve openly for the first time in the military and to allow Navy women to serve on submarines for the first time.

The newest move is being recommended by the Military Leadership Diversity Commission, established by Congress two years ago, and expected to send its report to Congress and President Barack Obama in the spring. The Army is doing its own internal study of the question as well.

The new report by a panel of retired and current military officers says that keeping women out of combat posts prohibits them from serving in roughly 10 percent of Marine Corps and Army occupational specialties and thus is a barrier to promotions and advancement.

“The Armed Forces have not yet succeeded in developing leaders who are as diverse as the nation they serve,” said the report, which also touched on recruiting and a range of other issues affecting the diversity of the force. “Minorities and women still lag behind white men in terms of number of military leadership positions.”

Women generally make up about 14 percent of the armed services. Of the roughly 2.2 million troops who’ve served in Iraq and Afghanistan, more than 255,000 have been women, said Pentagon spokeswoman Eileen Lainez.

Pentagon figures show that as of Jan. 3, 110 women had been killed in the war in Iraq compared with about 4,300 men. In the Afghan campaign, 24 women have been killed compared with more than 1,400 men.

Opponents of women in combat question whether they have the necessary strength and stamina. They also have said the inclusion of women in infantry and other combat units will harm unit cohesion, a similar argument to that made regarding gays, and that Americans won’t tolerate large numbers of women coming home in body bags.

Supporters of the change reject those arguments.

“It’s something whose time has come … a logical outcome of what women have been doing in Iraq and Afghanistan, where the Army and Marines have been essentially ducking the policy,” said Lory Manning of the Women’s Research and Education Institute. “They come up with the (term) ‘attaching’ someone to a unit as opposed to ‘assigning’ — but they’ve been doing it for nine years now.”

The current policy “represents a huge glass ceiling for servicewomen,” Anu Bhagwati, former Marine Captain and executive director of the rights group Service Women’s Action Network, said. “It is archaic, it does not reflect the many sacrifices and contributions that women make in the military, and it ignores the reality of current warfighting doctrine.”

Since promotion to many senior positions in the military is dependent on combat experience, changing the policy is a matter of fairness, she said.

The new report challenges predictions that a change would have ill effects on the units. “To date, there has been little evidence that the integration of women into previously closed units or occupations has had a negative impact on important mission-related performance factors, like unit cohesion,” the draft says.

“Furthermore, a study by the Defense Department Advisory Committee on Women in the Services actually found that a majority of focus group participants felt that women serving in combat in Iraq and Afghanistan have had a positive impact on mission accomplishment,” the report says of a previous independent study.

Top defense leaders have said they see the change coming someday. In answer to a question, Defense Secretary Robert Gates in September, for instance, told ROTC students at Duke University that he expects women to serve in special operations units, the kind of commando teams known for stealth missions. Gates said he expects women will eventually be allowed into special operations forces in a careful, deliberate manner.

The new report recommends a phased-in approach. First women in career fields and specialties currently open to them should be immediately assigned to any unit that requires that specialty. And the Pentagon and individual services should take steps in a phased approach to open to women additional career fields and units involved in direct ground combat, the report said.

Lainez said the department will review the recommendations when the report is delivered.

But regardless of what becomes of the policy, she noted that women will continue to be drawn into combat action.

“Women in the military continue to make tremendous contributions and profound sacrifices,” Lainez said in an emailed statement. “Women will continue to be assigned to units and positions that may necessitate combat actions (even within the current restrictions) — situations for which they are fully trained and equipped to respond.”